Factors affecting the synthesis of ovalbumin in chick oviduct will be examined. The 5'-terminal (cap) structure of ovalbumin mRNA will be determined. The protein which recognizes caps during initiation of protein synthesis will be purified and characterized. The degradation rate of ovalbumin mRNA in organ culture of chick oviduct will be measured both in the presence and absence of estrogen, and attempts will be made to understand the previously observed change in degradation rate.